I really don't see this "improving" the pve situation on Herocraft. Mobs are, in my opinion, already plenty strong. When leveling, you often fight hoards and hoards, and you do so quickly. Maybe you're using a swamp, maybe you're wandering around. Either way, it's a really tedious and really boring process. And at the end of the day, the only way that people establish a successful leveling strategy is by finding a swamp, setting up an outpost, and just grinding mobs at it.
This proposed change will not alter the way people treat pve, or really increase their enjoyability factor when leveling.
It will however, do a couple of things.
* Due to the fact that towns and their players have already been established, this grants "lucky" players who've wound up owning a prime location an unfair advantage. Many towns / groups place outposts in swampy areas due to Slimes being the best way to level. Some of these swamps are close to spawn, some of them are really far out. What this change will do here is grant those that already "control" a swamp at the far end of the map a GetMaxedQuick pass. There isn't any real opportunity for another town or group of players to cash in on this due to the town already having a strong presence in the area. (Note that this could be the inverse, a "GetDeadQuick" / "WhyWasteMyTimeHere" pass if the mobs prove to be too difficult to level with, similar to the nether.)
* Due to the much easier and calmer level of mobs near spawn, noobs will possibly keep their home bases near spawn at a greater rate than they have before. This is counterproductive, as active pvpers / gankers often congregate around spawn--leading to more severe deaths on the part of the noobs. They'd be force to choose getting stomped in pvp and having their stuff stolen, or venturing deep into the map and getting lost / destroyed by the stronger mobs.
* Due to the desire to reach for better leveling areas, it's possible that veterans will venture into enemy town territory, to "take over" their swamps. This could lead to creating / reviving some PVP hotspots, in an effort to level their fellow town members at a much quicker rate.
Overall, I think this effects pvp more than pve, and is an unnecessary change. It feels like a lot of effort to accomplish so little.